The Beckson Self Drain™ Opening Port is innovatively designed with an angled drainage ramp molded on the inside of the spigot. This design promotes drainage without having the hassle of making angled cuts in the hull. This also allows for thru-bolting, which is impossible in windows where an angled spigot extends below the bolt holes. The internal angle seats tightly against the gasket and lens, thus omitting an exterior water retention ledge present in most other ports. (No water-fall when you open the port after a rain.) Self Drain™ Opening Ports are ideal for mounting where installation is within 15° of vertical (with spigot length up to one inch). Longer spigots are available for vertical installations. For greater angles use Beckson Rain Drain™ Ports.